[fetch-later] Define new permissions policy deferred-fetch
1-Pager: https://docs.google.com/document/d/1P70kdENIByy3qWabN5rUPmBVkkANNSOM_jZynLnqINY/edit
This CL follows the guide to define a new permissions policy
deferred-fetch, which is used to gate the new fetchLater() API.
Relevant WPT are added in this CL, and the subsequent CL will further
use this policy to adjust the request quota.
In this CL, deferred-fetch is not added to chrome://settings/content
page. And no permission prompt for it.
- webappsec request: w3c/webappsec-permissions-policy#544
- "deferred-fetch" usage in fetchLater draft spec: https://whatpr.org/fetch/1647.html#request-a-deferred-fetch
- "deferred-fetch" policy discussion: WICG/pending-beacon#87 (comment)
- FetchLater Explainer: https://github.com/WICG/pending-beacon/blob/main/docs/fetch-later-api.md
Bug: b:40276121
Change-Id: I2db4dd7484610fefb50c463552155b220f13ac5d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5367481
Reviewed-by: Adam Rice ricea@chromium.org
Reviewed-by: Thomas Nguyen tungnh@chromium.org
Reviewed-by: Ian Clelland iclelland@chromium.org
Commit-Queue: Ming-Ying Chung mych@chromium.org
Reviewed-by: Yoav Weiss (@Shopify) yoavweiss@chromium.org
Reviewed-by: Takashi Toyoshima toyoshim@chromium.org
Cr-Commit-Position: refs/heads/main@{#1297320}